Automatic adjuster



July 2, 1940. H. c. BOWEN AUTOMATIC ADJUSTER Filed Feb. 8, 1959 I NVEN TOR. $75255??- C. Bows/v ATTORNEY,

Patented July 2, 1940 AUTOMATIC ADJUSTER Herbert 0. Bowen, Detroit, Mich, assignor to Hydraulic Brake Company, Detroit, Mich, a

corporation of California Application February 8, 1939, Serial No. 255,351

8 Claims.

This invention relates to brakes, and more particularly to means for adjusting the friction elements of brakes.

This invention comprehends a simple and eflicient means for automatically adjusting the friction elements of a conventional brake proportionately to the wear of the lining on the friction element so that .when the brake is at rest the friction element may be supported in proper spaced relation to the drum.

An object of the invention is to provide an automatic adjustment for the friction element 7 of a brake controlled by wear on the lining oi the friction element.

Another object of the invention is to provide an automatic adjustment .for the friction element of a brake operative to adjust the element proportionately to wear on the lining of the element.

Other objects of the invention will appear from the following description taken in connection with the drawing forming a part of this speciflcation, and in which,

Fig. 1 is a vertical sectional view of a brake illustrating the invention as applied; and

Fig. 2 is a sectional view substantially on line 2--2, Fig. l.'

Referring to the drawing for more specific details of the invention, Ill represents a fixed support or backing plateadapted to be secured to an axle or to an axle housing, and I2 represents a rotatable drum adapted to be secured to a wheel. The backing plate has arranged thereon a pair of spaced anchors l 4, and I6 and a pair of adjustable stops l8 and 20. A pair of corresponding interchangeable friction elements or shoes 22 and 24 are pivotally mounted on the anchors l4 and I6. Each of the shoes includes a web 26 supporting a rim 28 having suitably secured thereto a friction lining 30, for

' cooperation with the drum.

A fluid pressure actuated motor 32 is arranged on the backing plate between the friction elements or shoes, and connected to the force applying ends thereof, and a retractile spring 34 connects the shoes adjacent their force-applying (Cl. res-49.5

bore is inclined with respect to the web of the shoe and bias of the opening 36.

The screw it has on one of its ends an extension 42 for cooperation with the adjustable stop I8 or 20, and on the other end of the screw is a head M fitted for rotation in the opening 36. The head M" has thereon a friction lining 46 for cooperation with the drum, preferably of a lower coeflicient than the lining 30 and the rim 2B of the shoe. The head it and the lining t6 thereon are so disposed in the opening 36 that only a small section of the lining it adjacent its periphery may engage the drum. This facilitates in rotation of the screw to. The periphery of the head it is knurled, as indicated at 48. A spring 50 secured to the web of the shoe cooperates with the knurled surface it for inhibiting retrograde movement of the screw.

Under normal operating conditions, upon energization of the motor 32, the friction elements or shoes 22 and 2d are moved from their position of rest or retracted position into engagement with the drum it against the resistance of the retractile spring t l. This operation inherently results in wear of the friction lining til on the shoes, and this causes an unsatisfactory adjustment of the shoes when the shoes are returned to their retracted position.

In the instant invention, as the fining so on the shoes wears away the lining it on the head of the screw 40 engages the drum, resulting in slight rotation of the screw and movement thereof transversely of the shoe. This movement of the screw is proportionate to the wear on the lining 30, and retrograde movement of the screw is inhibited by the spring 50 cooperating with the knurled periphery of the head. Accordingly, when the shoes are returned to their retracted position, upon conclusion of a braking operation, the extension 42 engages the stop M or 20 and supports the shoe in proper spaced relation to the drum.

While this invention has been describedin' connection with certain specific embodiments, the principle involved is susceptible of numerous secure by Letters Patent is,-

1. A brake comprising a rotatable drum, 9. fric tion element associated therewith, .a retractile stop therefor, and a threaded member mounted ror;travei -=on"the element transversely thereof for cooperation: with the drum and stop.

2. A brake comprisinga rotatable-drum, a friction element associated therewith, .a retractile stop lforl the frictiOn element, anda threaded member'mountedl for travel on the element trans- I versel'y thereof having a part for cooperation with the drum and'another part for cooperation with "3. A brake comprising a rotatable drum, a friction element for cooperation therewith, a. retractile stop forthe element, and a threaded member mounted 'for travel on the element with its respective ends arranged for cooperation with the drum andistop. g

4. A brake comprising a rotatable drum, a fric- I tion element for cooperation therewith, a retractile stop associated with the element, and a screw mounted for travel on the element having a head for cooperation with the drum and an end for cooperation with the stop.

. 5. A brake comprising a rotatable drum, a frictio'n element for cooperation therewith, a retrac tile stop associated with the element, and a screw mounted ion-travel on the element transversely thereof and'iricli'ned with relation thereto having a head for cooperation with the drum and an end for cooperation with the stop.

6. A brake-comprising a. rotatable drum, a friction element for cooperation therewith, a retractile stop associated with the element, a screw mounted for travel on'the element transversely thereof and inclined with relation thereto, a head on the screw, a friction lining on the head for cooperation with the drum, and a part on the .screw for cooperation with the stop.-

' 7. A- brake comprising a rotatable drum, 8. friction element for cooperation therewith having an' opening therein, a retractile stop associated with the element, a screw mounted for travel on the element transversely thereof and inclined with relation thereto, a head on the screw received by the opening and adaptable for engagement with the drum, and a reduced end on the screw for cooperation with the stop.

' 8. A brake ccimprising a rotatable drum, a friction element for cooperation therewith having an HERBERT C. BOWEN. 

